Postern

v0.1 · the developer preview

Your agent knows the world.

Put it to work on yours.

Ask it about your:moneyhealthmailcalendarcontactshome

— via Postern, on hardware you own.

Install Postern

github.com/getpostern/postern

  • Open source (Apache-2.0)
  • Agents never see your passwords
  • Zero telemetry
  • Any agent, over MCP
financeCumulus nummorum
healthLamprocapnos salutis
calendarDiscus mensis
mailEpistola volans
contactsMyosotis amicorum
homeDomus lanterna

ANY AGENT, ONE PLACE

Agents work better with Postern.

3 agents hold 3 keys, and none of them needed custom code.

HOW IT WORKS

New agents plug into Postern, not into every account you own.

inputs · your sources outputs · ai agents
How Postern works CONNECT ONCE → ENCRYPTED → GRANTED PER AGENT → RECORDED
finance Plaid · SimpleFIN
health WHOOP · Apple Health
mail Gmail · Microsoft · iCloud
contacts Google · Microsoft · iCloud
calendar Google · Microsoft · iCloud
home Home Assistant

you decide who gets a key

Claude· Scheduler
calendar only
ChatGPT· Inbox aide
mailcontacts
OpenClaw· Bookkeeper
finance only
any AI agent
you choose the scope

ia small, owner-only door

iione credential, encrypted once

iiigranted · not granted

iv…and the refusal, recorded

WHY POSTERN, AND NOT GLUE

The agent asks for what it needs.

last month’s calendar… 14 bank statements… the whole inbox… every time

WITHOUT POSTERN

The agent reads an index first. Then it asks for the 6 rows it actually wants.

just the slice it needs already in one shape from a local cache live from the source when it matters

The second question costs no more than the first.

Models change. Your context should not.

The agent that leaves takes nothing with it. Your connections and your grants stay.

custom glue dies the day you switch agents

THE CONSOLE

How you connect an agent.

Mint an agent key

Nameledger-keeper
financegranted
calendargranted
mail
contacts
health
home

Postern shares nothing until you grant a sector · ungranted sectors stay off

The key, shown once

wJ4kT9••••••••••••••••3hQe

shown once — copy it now

The agent’s whole config is your Postern’s address plus this key. It never holds a password of yours.

Its first entry, recorded

09:14 ledger-keeper read finance

✓ allowed

The agent is on the record from its first minute. One place to revoke it.

Postern recorded every step.

Read the security model →

WHAT RUNS TODAY

MONEY

Plaid · SimpleFIN

HEALTH

WHOOP · Apple Health

MAIL

Gmail · Microsoft · iCloud

CALENDAR

Google · Microsoft · iCloud

CONTACTS

Google · Microsoft · iCloud

HOME

Home Assistant — reads, and acts

Postern reads from all of them. Only Home Assistant accepts actions today.

INSTALL POSTERN

Three commands, on hardware you own.

Hand the setup to your agent.

FOR YOUR AGENT

Paste one line into Claude Code, Cursor, or any coding agent. The agent installs Postern, wires itself in, and stops for you at every sign-in.

Follow this file and set Postern up for me:
https://raw.githubusercontent.com/getpostern/postern/main/setup-with-your-agent.md
The docs explain how agent setup works →